Paget’s disease of the bone is a relatively common disease of middle-aged and elderly people in which there is excessive and abnormal bone remodeling. The condition results in extensively vascularized, weak, enlarged, deformed bones that are increasingly prone to subsequent complications.

Determining the frequency of occurrence of Paget’s disease is inherently imprecise because many affected people are asymptomatic. The disease is estimated to affect approximately 3% of the population 40 years of age or older. Males are more commonly affected at a ratio of 1.8:1.

The exact etiology of Paget’s disease remains unknown. Genetic and nongenetic contributions have been implicated, including factors related to viral infection, elevated parathyroid hormones, autoimmune deficiencies, connective tissue, and vascular disorders.